The North American Species of Crepidotus

103. Crepidotus subluteus sp. nov.

Illustration: Fig. 177.

Pileus 8-15 mm latus, sessilis, flabelliformis, albus, pubescens, margine incurvatus. Lamellae albidae deinde ”yellow ocher," angustae demum medio-latae, confertae vel paene subdistantes. Sporae 7-9 x 4.5-5.5 µ ellipsoideae, punctatae, cumulatae “yellow ocher." Basidia 26-30 x 6-8 µ, tetraspora. Pleurocystidia desunt; cheilocystidia 22-34 x 6-21 µ. Cuticula ex hyphis repentibus composita, hyphas erectas, sinuosas vel in spiram volutas sine colore gerens. Fibulae adsunt. Specimen typicum in Herb. Univ. Mich.; lectum prope Pellston Hills, Mich.; July 17, 1961, 0. K. Miller 1047.

Pileus 8-15 mm broad, sessile, flabelliform, pure white, pubescent under a lens, margin incurved. Lamellae whitish becoming "yellow ocher," narrow to moderately broad, close or nearly subdistant, edges even or slightly rough.

Spores 7-9 x 4.5-5.5 µ, ellipsoid, inequilateral in profile, obscurely punctate, color in deposit: near "yellow ocher." Basidia 26-30 x 6-8 µ, 4-spored. Pleurocystidia none; cheilocystidia 22-34 x 6-21 µ, clavate, ventricose, at times with a neck, or subvesciculose to spathulate. Gill trama interwoven, hyphae 6-12 (20) µ broad, often short-celled. Pileus trama interwoven. Cuticle of repent hyphae, bearing a turf of crooked or coiled, colorless, non-incrusted hyphae, 2-5 µ broad. Clamp connections present.

Habit, Habitat, and Distribution: On dead Ulmus, Michigan, July.

Material Studied: MICHIGAN: Miller (MICH) 1047, type, from Pellston Hills, leg. O. Miller, July 17, 1961.

Observations: This species is characterized by its pure white pileus, its yellow ocher gills and spores, and broad cheilocystidia. It is near C. epibryus and C. eburneus, the former with pinkish gills, and the latter with clay-brownish gills.